First of all - Congratulations on your new position. You will find that, despite the hard days, it can be fun and rewarding.
1 & 2 - It sounds like you are better off not having the prospective SM around. If the former SM was not attempting to run the program as outlined by the BSA, then it is probably a good thing that someone new is taking the job.
As far as 'Scoutmaster Stuff', there are some useful materials (books, etc.) usually available at the scout shop or online. I'm not sure what else would be included as 'Scoutmaster Stuff'. Any equipment (tent/camping gear/etc.) and materials COULD have been purchased by the previous SM. If that is the case, then it is his and you have no right to it. If it was purchased with troop funds, then it belongs to the troop and he stole it. Any records (advancement & financial) should be handled by the committee, but if this info is included the the 'Scoutmaster Stuff', then he has no need of it, and you do need it. Perhaps a civil conversation with the person who has the stuff will get you any important info you can't replace. Based on your other comments, this civil conversation is more likely to be you than anyone on your committee.
3 & 4 - You don't have a committee. The chair is unwilling to work with you and you have never met any of the others. If this continues to be the case, then it is time to recruit a new committee that is willing to do their jobs (including training). The job of the committee is to provide program support for the troop. This is mostly done by meeting with the SM on a regular basis, so that the committee knows what support is needed. SM should be meeting regularly with the whole committee. How can they pretend to be a troop committee if they won't work with the troop and the selected leader(s)? In my corner of the world, working committees are rare. It makes the SM job harder, but you and your ASMs can share the responsibilities if the committee is not doing it. In the absence of a working committee, have your PLC work out an annual budget, and work with it regardless of committee approval.
5 - Get your youth leaders together for some training ASAP. The training materials include job descriptions for each position, and a basic outline to train the boys how to work together and how a troop should be run. Yes, you can provide guidance for youth who want to know how to do their jobs. Aside from health & safety issues, the primary job of the SM is to train the youth leadership. Your ASMs should help in guiding the youth leaders. Perhaps there is an ASM or Committee Member or SPL who could help the QM so that you don't have to divide your time with ALL the youth leaders.
6 - There is nothing wrong with having expectations of your SPL. If he is unwilling to do the job (either be at meetings to take charge, or make sure ASPL is prepared in his absence), then he should be replaced. Mom should not run the re-election campaign for SPL. Talk with the boy (Scoutmaster Conference) and see what he wants to do as SPL. He is in charge of the Patrol Leaders Council, and if he doesn't want to take the time to lead, then he shouldn't have the position.
Other advice from a former SM:
Don't expect the troop to run perfectly now. They are learning what a real troop is. The boys and parents will support you as you transition to a better troop program. It will likely take time for them to readjust their expectations. (It took about 3 years for my troop to readjust their expectations and really take hold of the program BSA and I wanted to implement). Add or Change things a few at a time. If the troop is suddenly a new program, you may have trouble getting them to accept all the changes.
In my 10 years as SM, I only had the support of a working committee for about 2 years. Run the program as best you can, with or without their support.
Have a regular Scoutmaster Conference with every boy regardless of their advancement progress. This is how you will know what program they want, and what they see as needing improvement. This is also a good time for you to continue helping your youth leaders to learn and do their jobs.
I would start building the new troop program by making sure you have a working outdoor program. Make sure there is a camp or outing scheduled every month. Keep to the schedule. ("In this troop we camp every month, weather or not.") If you cancel plans, the boys will learn to expect cancellations. Make sure each camp has some activity/purpose besides just camping. If camp means setup in the dark, sleep, eat, packup, and go home, it is not really an outdoor program.
Work with your PLC to make an annual plan. Find out what the boys want to do and include those things in the plan. Make sure to get your district and council events on the troop calendar. The easiest camp planning for a troop is to attend the district/council camps. Sometimes the way you propose a calendar item makes all the difference. Don't ask, "Do you want to participate in the Scout-O-Rama this year?" Instead ask, "What would you like to do in our booth at the Scout-0-Rama this year?" Ask "How many troop service projects do we want to do this year?" "What camping and outdoor activities do you want to plan?" "Which scouting skills and/or merit badges should we work in January?" Don't dismiss the value of an OCCASIONAL night when they just get together to do something fun (and build friendships and team). MOST troop meeting nights should have a planned scouting purpose.
In my troop we planned swimming on the first week of every other month. The other months we would spend the night focusing on the "Duty to God" program of our Charter Organization. Plan time for a quarterly Court of Honor, service projects, fund-raisers, etc. Other nights in the month would be filled in with learning/practicing skills for the upcoming outdoor activity, or focusing on advancements. We usually chose 1 merit-badge to focus on each month, about 6 of them Eagle required.
Eagle Scout 1987
OA Vigil Honor 1986
Fox - WE7-590-05-2
Currently - Troop/Team/Crew Advancement Chair & Dist Webmaster
Previously - SM, MC, CM, ACM, ADL, ASM, COR, Dist Camp Chair, PL, SPL, Scribe, Songleader, JASM, OA Chapter Officer, ...